<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>案例1</title>
</head>

<body>


    <script>
        alert(`
            12345:${typeof 12345}\n
            'abc':${typeof 'abc'}\n
            document:${typeof document}
        `)
    </script>
</body>

</html>